Retaining wall structures that use horizontally positioned soil inclusions to reinforce an earth mass in combination with a facing element are referred to as Mechanically Stabilized Earth (MSE) structures. MSE structures can be used for various applications including retaining walls, bridge abutments, dams, seawalls, and dikes.
The basic MSE technology is a repetitive process where layers of backfill and horizontally placed soil reinforcing elements are positioned one atop the other until a desired height of the earthen structure is achieved. Typically, grid-like steel mats or welded wire mesh are used as earthen reinforcement elements. In most applications, the reinforcing mats consist of parallel transversely extending wires welded to parallel longitudinally extending wires, thus forming a grid-like mat or structure. Backfill material and the soil reinforcing mats are combined and compacted in series to form a solid earthen structure, taking the form of a standing earthen wall.
In some instances, a substantially vertical concrete wall may then be constructed a short distance from the standing earthen wall. The concrete wall not only serves as decorative architecture, but also prevents erosion at the face of the earthen wall. The soil reinforcing mats extending from the compacted backfill may then be attached directly to the back face of the vertical concrete wall. To facilitate the connection to the earthen formation, the concrete wall will frequently include a plurality of “facing anchors” either cast into or attached somehow to the back face of the concrete at predetermined and spaced-apart locations. Each facing anchor is typically positioned so as to correspond with and couple directly to an end of a soil reinforcing mat.
Via this attachment, outward movement and shifting of the concrete wall is significantly reduced. However, in cases were substantial shifting of the concrete facing occurs, facing anchors may be subject to shear stresses that result in anchor failure. Although there are several methods of attaching the soil reinforcing elements to the facing anchors, it remains desirable to find improved apparatus and methods offering less expensive alternatives and greater resistance to shear forces inherent in such structures.